第1个回答 2013-01-28
是被动语态
一般现在时am/is/are done
一般过去时was/ were done
一般将来时will/ shall be done, am/is/ are going to be done, am/is/are to be done
现在进行时am/is/are being done
现在完成时have/has been done
过去进行时was/were being done
过去完成时had been done
过去将来时would/should be done